In December, the highly anticipated new guidelines for managing high blood pressure appeared in the online version of The Journal of the American Medical Association (JAMA). They suggest that most hypertensive patients aged 60-years-old or more should aim for a blood pressure level under 150/90 mm Hg.
That surprised many physicians, since the target had previously been set at 140/90 mm Hg. “The fear is that the higher number creates confusion and that primary care physicians will not work as hard at lowering blood pressure,” says Andrew Miller, MD, a cardiologist and hypertension specialist with CVA in Birmingham.
The new target number occurred because the Eighth Joint National Committee (JNC 8) — appointed by the National Heart, Lung and Blood Institute (NHLBI) — created the new guidelines based solely on randomized controlled trials. “This document is evidence-based only,” says Miller. “The government tried to avoid expert opinion as much as possible. That wasn’t the case with the last committee. This time, they wanted to put on paper the things that we could really hang our hat on and firmly say was factual.”
The panel systematically analyzed the hypertension literature from 1966 to date. “When they looked at the trial database, it was hard to prove that lowering blood pressure with medications below 150/90 was beneficial, though they found clear evidence that 160/100 did show notable risk,” says Miller. “So they loosened the threshold for blood pressure reduction.”
The new target number is also higher than other respected nations. “We have other guidelines from places like Canada and England who have been updating theirs yearly for the last 14 years,” says Miller.
England recommends the widely accepted 140/90 for hypertensive patients under 80. Only for patients over 80, do they match the looser U.S. guideline of 150/90. But again, Miller points out, “this target number was from an expert panel that included primary care and hypertension experts. Not just evidence-based data.”
Last June, NHLBI fueled more guidelines controversy by backing off of officially sanctioning their publication. They had decided to discontinue developing clinical guidelines of any kind, including the hypertension guidelines. Instead, they handed off the responsibility for completing the task and publishing them to specialty organizations, such as the American College of Cardiology and the American Heart Association. However, in December, the JNC panel, after five years of work, published their version, noting that they did not reflect the views of the NHLBI.
Miller believes one reason for the pullout may be a concern that if the government sanctions a guideline statement, then it would become too rigidly interpreted. “A payer could then penalize a provider and say they had not followed what the government says. So I think there was concern that target numbers released by the government could create mandates,” he says. “But if professional societies do this, then it’s less a mandate on a primary physician to get to that goal.”
The guidelines were not all filled with controversy, though. They included nine recommendations and a flow chart to help physicians determine treatment. One section compared the benefits and drawbacks of various drugs or drug classes on specific health outcomes in adults with hypertension. It’s raised no notable criticisms, says Miller. “The only thing up in the air with the JNC guidelines is the target number.”
Though vital to determining treatment protocol, the target number often holds no real meaning to patients. “Because when you treat blood pressure, nothing happens to people. It should be an invisible treatment,” Miller says.
To give the target number a relatable value, Miller recommends “telling patients that with every 20 on top and 10 on bottom, they double their risk of stroke, heart attack or dying. Patients can believe in that.”
Though the JNC guidelines raised the target number for those over 60 with hypertension, other age brackets remained the same. Blood-pressure patients aged 30-59 should shoot for a diastolic goal under 90 mm Hg. However, the panel did not set a systolic goal, citing a lack of evidence to make that determination. Therefore, they recommend a target under 140/90 mm Hg for this age group.
Miller points out that the ideal blood pressure for any adult patient still remains at 115/75. “But that doesn’t mean that prescribing drug therapy to hypertensive patients to attain that ideal is beneficial. That’s an observed ideal, not meant to be achieved by treatment.” He says the guidelines sought to determine the target number that would achieve the lowest risk of stroke or dying through the use of medications for those with hypertension.
The guidelines being composed by the professional societies could come out any time, and yet another new target number could be released. The societies have had the data and analysis from the JNC panel for over a year and could likely release their official document in the next few months.
“The overwhelming message should be that there’s still more work to do in treating blood pressure,” says Miller. “Fifteen years ago, 31 percent of people with hypertension had their blood pressure under control. In 2010, it was 47 percent. We’ve made a lot of headway simply with meds. And the fear with this looser target number is that we’ll lose ground on blood pressure control in the U.S.”